Steam-generator



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STEAM GENERATOR. v

Patented Apr. 26, 1898.

(No Model.) 7 SheetsSh'eet 2. 0. D. O RVIS.

STEAM GENERATOR; No. 603,223. Patented Apr. 26,1898.

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(No Model.) 7 Sheets-Sheet 3.

0; D. 'ORVIS.

' STEAM GENERATOR.

No. 603,223. v r Patented Apr. 26, 1898.

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(No Model.) '7 Sheets-Sheet 4Q" 0(1). ORVIS. I

STEAM GENERATOR. No. 6 03,223. v v fPaitented-Apr. 26,1898.

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STEAM GENERATOR.

Patented Apr. 26, 1898.

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, furnace shown in Figs. 6, 7, and 8.

UNITED STATES i PATENT OFFICE.

OREL D.- ORVIS, ST. LOUIS, lVIISSOURI.

"STEAM-GENERATOR.

srnorrrcArron formingpart of Letters Patent No. 603,223, dated April 26, 1898.

Application filed June 14,1897.

To all whom it may concern.-

Be it known that I, OREL D. ORVIS, a citizen of the United States, residing at St. Louis, in the State of Missouri, have invented certain new and useful Improvements in Steam- Generators; and I do declare the following -to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to .the letters of reference marked thereon, which form a part. of this specification.

This invention relates to that class of steamgenerators in which the downdraft principle of combustion is employed; and its objects are to increase the efficiency of such generators by so disposing the circulating-pipes that the area of the heating-surface .is increased, and to strengthen and render more durable the construction of the water-tube grates.

A further object is to secure an improved means for precipitatingupon a lower updraft grated surface the cinders falling from the downdraft-furnaces. v

These objects are obtained by the arrangement of parts as hereinafter fully set forth. 1 In the accompanying'drawings, Figure l is a front elevation of my improved steam-generator. Fig. 2 is a central longitudinal vertioal section on the line 2 2 of Fig. 1. Fig. 3 is a sectional view, partly in elevation and some of the parts being broken away, on the line 3 3 of Fig. 2. Fig. 4 is a detail plan section on the line 4 4 of Fig. 2. Fig. 5 is a detail transverse vertical section on the line'5 5 of Fig. 2. Fig. 6 is a transverse Vertical section immediately back of andpartly through the furnace-front and'a portion of the front being shown in elevation, the invention being applied to the Lancashire form of steamboiler. Fig. 7 is a plan section onthe line 7 7 of Fig. 6. Fig. 8 isia vertical section on the line 8 8 of Fig. 6; and Fig. 9 is a detail of the covering of the fire-box in theform of The generator isset in masonry, as usual. The front wall Amay be of metal, but is preferably of masonry, as shown. The side walls are represented at A and the rear wall at A A transverse partition a, of masonry,

Serial No. 640,754.. (No model.)

extending from side wall to side wall and from the furnace-floor to the crown-sheet of the boiler, separates the fire-boxes or furnace proper from the combustion-chamber and is centrally apertured to form a flue-passage. In the construction represented in Figs. 1 to 5 the ordinary tubular boiler X is shown.

Two downdraft-furnaces are used and their grate-bars consist of an upper and lower series of water-tubes, designated, respectively, B b. The tubes of the two series are not set staggered, as has heretofore been usual, but the tubes of the lower series I) are directly below those of the upper series, and interposed between each pair thus formed is suitable masonry e, whereby weight resting upon the uppertubes is transmitted in'part to the lower set. By this construction the strength of the grated surface is greatly increased, so that it becomes possible to reduce the thickness of the walls of the tubes without danger of causing them to sag under the .weight of the fuel. By this means the efficiency of the tubes for the generation of steam is of course increased, and, furthermore, it becomes poss'ible to utilize thinner tubing throughout the entire circulating system without danger from the unequal expansion which would result from the use of tubing of varying thicknesses. Furthermore, the metal ofthe tubing when thin is better protected by reason of the more rapid absorption of the heat by the water and the life of the tubular grate-bars is thereby prolonged; Another decided advantage in this construction arises directly from the use header 0 extends from the floor of the generator to within a short distance of the crownsheet of the boiler and supports an inverted arch K, which contracts the discharge-flue from the combustion-chamber forward of the header to a comparatively small vertical width for purposes hereinafter described, the header and the arch K forming a bridge-wall. The tubes B I) extend through the partition a; but the masonry e is not continued back of this partition.

The inner side wall of each of the fire-boxes of the downdraft-furnaces is comprised of a series of water-tubes E, extending from the header G to the header D, and masonry e, filling the interspaces between such tubes, and masonry a, filling the space between the upper one of the tubes E and the crown-sheet of the boiler. Neither the masonry e nor e extends back of the walla. A similar series of tubes F extends from the rearward to the forward header across the upper portion of these fire-boxes. The inner side walls of the fire-boxes of the two downdraft-furnaces are spaced apart, so as to form therebetween the combustion-flue Y, leading to the central aperture in the partition a, and I prefer to incline these side walls apart from below upwardly, so that the flue Y has a comparatively contracted throat, but incloses a considerable area of the crown-sheet of the boiler, thereby exposing a very considerable surface of the boiler to the direct action of the burning gases.

An updraft-furnace is located below the downdraft-furnaces, as shown at G, and receives the droppings from the downdraft-furnaces, so as to insure the complete combustion of the fuel. As it is not desirable to provide an updraft-furnace having as great width as the combined width of the downdraft-furnaces, I locate it centrally as to the generator, and at each side of it I place a rotatable cylinder II, made of any suitable refractory material, such as fire-clay, and mounted upon an axle h, journaled in the front wall and in the partition (1, the forward end of the axle projecting beyond the front wall and being squared for the convenient application of a crank-arm. Any cinders which may lodge upon the cylinders II are precipitated upon the grated surface G by their rotation.

Fresh fuel may be fed directly to the updraft-furnace, if desired, feed-doors 9 being provided for that purpose. An ash-pit is below the updraft-grates, and access to it is gained by means of the doors g.

A water-leg L leads from the bottom of the boiler X at its rearward end to the lower portion of the header 0, and water-legs M M lead from the upper portion of the headcrD, one at each end, to the upper portion of the boiler X. The water-tubes B, b, E, and F are inclined upwardly from the rear header, so as to promote circulation, and in order that they may be expanded into the headers the latter are tilted baekwardly, so that their faces'are perpendicular to the tubes. The header C is extended below the junction with it of the tubes 1), so as to serve the purposes of a mud-drum, and it is provided with a blow-off pipe Z. To prevent the accumulation of steam at the top of the header 0, ventpipes c are provided leading from the header to the boiler.

The front header D is apertured to provide feed-openings for the downdraft-furnaces, these openings being provided with doors, each comprising a frame 0, hinged at its side, as shown at 0, so as to swing horizontally, and of a central panel P, hinged at its top to the frame 0, as indicated at p p. The panels P are openable for the purpose of providing draft, and swing upwardly, so as to prevent material loss of heat by radiation. Each of the doors is provided with suitable means, such as a simple form of ratchet P, for supporting the panel at any desired elevation.

The front wall of the header D is apertured opposite the ends of each of the water-tubes entering the header and also opposite each of the water-legs M. These apertures are closed by suitable covers, as shown at B, b, E, F, and (1. These hand-hole closures are of a well-known type, comprising a plate within the wall, an arch without the wall, and a draw-bar connecting the two members and carrying a nut upon its outer end, this form of closure being preferred, as the plates are held in place by pressure from within, and a tight joint is not dependent upon a strain applied to the draw-bar. To facilitate the manipulation of the hand-hole covers, certain of the holes may be oblong, and, if desired, may be large enough to provide access to two of the tubes.

In applying the invention to a Lancashire boilerthat is to say, a boiler 2, having a greater diameter than the ordinary tubular boiler and having large combustion-fines, as 2 .2the furnace proper is located forward of the boiler and spaced apart therefrom, as is usual in this type. The headers are vertical and not tilted, as in the generator already described, an d consequently the watertubes connecting the headers are horizontal. In generators of this type, and, if desired, in the generator already described, the outer side wall of each of the downdraft-furnaces may also be provided with a series of watertubes, as shown at F, connecting the two headers. In the Lancashire type the rearward header formsthe back wall of the f urnaee proper, and its covering or roof f is supported by the water-tubes F, and in this construction these tubes are located not only across the top of the fire boxes, but also across the top of the combustion-flue Y.

Two flue-openin gs Q Q are formed through the header 0, and fines inclosed by masonry, as shown at q, lead from these flue-openings to the fines z z of the boiler, passing through the front plate 2 of the boiler. In this type of boiler also I find it desirable to provide two water-legs L for serving the header 0 with water from the boiler, one being located near each end of the header.

The vapors distilled from the three furnacesthat is, from the two downdraft and the one updraft-meet at the throat of the flue Y. Those coming from the downdraftfurnaces have lost some of. their heat by reason of their contact with the water-tube gratebars but their temperature is raised by the hot vapors ascending from the lower furnace,

and they enter, the flue Y at a kindling temperature. I leave the space between the lower of the tubes E and the inner of the tubes B open, so that air passes therethrough into the flue and promotes the combustion of the gases.

By admitting air in this manner it enters the flue hot, and hence does not materially reduce the temperature of the burning gases and thereby check their combustion.

Within the combustionchamber back of the partition 01. the gases are caused to spread laterally, so as to circulate through the interspaces between the pipes E and the pipes F by reason of the contracted flue-opening over the bridge-wall, whereby the rearward portions of the water-tubes render an efficient service in the generation of steam. The wide expanse of heating-surface presented to these vapors as they pass backwardly and deflect: ing them upwardly to the discharge-flue over the bridge-wall and comprising the front wall of the rear header 0 also robs the vapors of much of their heat, especially as the header contains the coolest water in the entire system. The inverted arch of masonry K not only subserves the ordinary function ofa' bridge-wall, but extracts from the vapors considerable of their heat and transmits it to the water in the header 0.

By drawing the water from the bottom of the rearward end of the boiler in the type of generator first described, passing it through a circulating system, all parts of which are inclined upwardly, and returning it to the front of the boiler and at a greater elevation than that from which it is takentherefrom I am able to provide for the very rapid circulation of the water, thereby greatly assisting in accomplishing the desired result of extracting from the vapors of combustion the largest possible percentage of their heat andutilizing it in the production of steam.

I claim as my invention- 1. In a steam-generator, the combination with a boiler and a pair of downdraft-furnaces spaced apart to form therebetween a flue, and a partition at the back of the furnaces and having an aperture in register with the said flue, of a bridge-wall back of the partition, water-tubes for the grate-bars of the furnaces and water-tubes forming parts of the adjacent side walls of. the fire-boxes of the furnaces, both sets of such tubes extending backwardly to the bridge-wall, and service and return connection between such tubes and the boiler. 1

2. In a steam-generator, the combination with a boiler and a pair of downdraft-furnaces spaced apart to form therebetween a flue, and a partition at the back of the furnaces and having an aperture in register with the said flue, of a chambered bridge-wall back of the partition, water-tubes for the gratebars of the furnaces and water-tubes forming parts of the adjacent side walls of the fireboxes of the furnaces, both sets of such tubes extending backwardly to the bridge-wall and being in connection with the chamber thereof, a water-leg leading from the boiler to the chamber of the bridge-wall, and return connection between the forward end of the tubes and the boiler.

3. In a steam-generator, the combination with a boiler and the settings therefor including side walls and a transverse centrallyapertured partition, of a header back of the partition and constituting a bridge-wall, a header forming a part of the furnacefront,two sets of water-tubes connecting the headers and constituting grate-bars fora pair of downdraft fire-boxes, two sets of water-tubes connecting the headers and arranged in series leading from the plane of the grates toward the boiler and forming parts of the inner walls of the'fire-boxes, such walls being spaced apart to form a flue registering with the aperture of the partition, and connection between the headers and the boiler. V

4. In a steam-generator, the combination with a boiler and the settings therefor including side walls and a transverse centrally-apertured partition, of a header back of the partition and constituting a bridge-wall, a header forming a part of the furnace-front, two sets of water-tubes connecting the headers and constituting grate-bars for a pair of downdraft fire-boxes, two sets of water-tubes connecting the headers and arranged-in series leading from the plane of the grates toward the boiler and forming parts of the inner walls of the fire-boxes, such walls being spaced apart to form a flue registering with the aperture of the partition, a series of tubes connecting the headers and crossing the upper portions of of a lower set of water-tubes, the members of each set being vertically alined, masonry filling the interspace between the upper and lower members of each pair of tubes, whereby the lower set aids in supporting the fuel.

7. In a downdraft-furnace,the combination with an'upper set of water-tube grate-bars,

of a lowerset of watertubes, the members of each set being vertically alined, the lower tubes being of less diameter than the upper tubes, and mechanical connection between I 7 each of the lower tubes and the tube imme with a boiler, and a furnace, of a bridge-wall combining a metallic chest, and an inverted arch of masonry resting upon such chest, and I 5 induction and eduction tubes connecting the chest with the boiler.

In testimony whereof I aflix my signature in presence of two witnesses.

OREL D. ORVIS.

lVitnesses:

A. J. HOERNEY, ARTHUR KINER. 

